Mesa 7i96 Output Wiring

5V/12V/24V Relay Module,4 Channel Optocoupler Relay Module Board High & Low Trigger (24V) www.amazon.ca/dp/B07QKLKPBJ/ref=cm_sw_r_cp_tai_rnFpFbZ9G2PSN

These relay boards are opto isolated on their inputs so I should not need a flyback diode correct?

PCW may correct me but Flyback diodes are only necessary where its an electromechanical relay (with a coil). Also I don't understand why you would bother with relay boards when the 7i96 has relays built into the outputs.

The relays on those boards are electromechanical with coils. They are optically isolated so I don't think a flyback diode would be required but I wanted to confirm.

The relays are for future expansion in case I need to switch >2A and >36VDC and/or an inductive load. May never get used but they are there if I need them.

rodw wrote: Also I don't understand why you would bother with relay boards when the 7i96 has relays built into the outputs.

Probably because of all the conflicting advice out there! Has the general consensus change that a relay here truly isn't necessary for switching something like a plasma torch?
forum.linuxcnc.org/27-driver-boards/3659...6-and-thcad?start=10

For the sake of completeness I would like to add to this thread that PCW also recommends the current should be limited to 2-5A at each output relay, so if your PSU is larger than that you should put a fuse on the output circuit.
forum.linuxcnc.org/27-driver-boards/3981...output-fuse-s#178843

Also for completeness, I'd also like to know if these relay modules boards require a flyback diode.

It looks like you have one guy recommending the use of relays. Its pretty clear in the manual So they can switch up to 36V 2 amps. I think you need to get the polarity right being SSR's
There is nothing on a plasma machine that needs 2 amps. Just check what is said about the voltage in the torch on signal for your machine to be safe.

With Hypersensing, the only output required is the torch on relay.

But yes if the relay has a coil, add the flyback diode. It won't do any harm. I did not do this initially on my 7i76e switching panel relays and it all survived but subsequently added them after reading comments by PCW. Just a IN4001-4007 or similar. Maybe your relay board does not need it but the Mesa card costs a lot more than it!

Now I've replaced my torch on relay with a SSR, I don't use any flybacks.

I am a bit lost as well and the pictures are gone. Is this correct?Thanks so much